On a similar plane, I smoothly wrapped the saddle area of the wing with Saran Wrap. Then I squeezed a small bead of RTV Silicone onto the wing saddle and mounted the wing for a day. After it was cured, I unmounted the wing, peeled the plastic wrap off the RVT and trimmed away the excess from the saddle area. Another full day to let it air cure, and it was ready to fly, perfectly sealed.